Fire alarm contact device



m 2 R U 5 m 10 m G L W 0 "(L 4mm; 7!. m EM 2 2 H a L g D Q y 4 v. H B AQ F U FADKLLA FIRE ALARM CONTACT DEVICE Filed Feb. 25, 1946 New. 26 319Patented Nov. 26, 1946 UNITED STATES PATENT OFFICE FIRE ALARM CONTACTDEVICE Dante Padilla, Vallejo, Calif.

Application February 25, 1946, Serial N 0. 650,061

2 Claims.

This invention relates to improvements in fire alarms, and hasparticular reference to a contact mechanism therefor.

The principal object of this invention is to provide a plurality ofcontact devices which act as switches under certain conditions to closea circuit and cause an alarm, either visual or audible.

A further object of this invention is to produce a device of thischaracter which is neat in appearance and therefore one which will notdetract from the appearance of the room in which it is installed; also,a device which is economical to manufacture and easy to install.

A further object is to produce a device wherein the various parts aresimple, mechanical units which will be positive in operation under allgiven conditions and therefore a device which cannot become inoperative.

A further object is to produce a device which may be attached to anyordinary signaling circuit without alteration in its construction orwiring arrangement.

A further object is to provide a device wherein a definite contact ispositively assured through the digging action of the ends of the contactspring.

A further object is to provide means whereby the spring tension of thespring contact also serves to cause collapse of the fusible block.

Other objects and advantages will be apparent during the course of thefollowing description.

In the accompanying drawing forming a part of this specification and inwhich like numerals are employed to designate like parts throughout thesame,

Fig. 1 is a top plan view of one of my contacts.

Fig. 2 is a side elevation of Fig. 1.

Fig. 3 is a view similar to Fig. 1, with the top removed and showing thewiring diagram, and

Fig. l is a view similar to Fig. 3 showing the parts in position tocause an alarm.

Many large fires are due to the fact that they are not discovered untilthey have gained considerable headway, and it would, therefore, beadvantageous if an alarm were sounded at the time of the beginning ofrise in heat within a given area.

Applicant has, therefore, devised a switch or contact device wherein afusible metal block is positioned between a support and a contact springin such a manner that the spring is kept from completing a circuitbetween the two contact connected to the alarm circuit. However, uponthe heating of the block to a predetermined temperature, the same willbecome soft and allow the 2 spring to move to a position to complete analarm circuit, so that warning will be given after a predeterminedtemperature has been reached.

In the accompanying drawing wherein for the purpose of illustration isshown a preferred e-. bodiment of my invention, the numeral 5 designatesthe base of my device which is made of any non-conducting material, andthe numeral 6 designates the cover therefor.

The base and the cover are mounted at any convenient point by a screw 1.

Within the base 5 I provide a recess 4, in which is mounted a pair ofspaced contacts 8 and 9. The contact 8 is connected by a wire H to oneside of an electrical circuit, while the contact 9 is connected by awire [2 to an'audible signal l3, which signal is in turn connected by awire M to the opposite side of the circuit.

In order to complete the electrical circuit between the contacts 8 and 9I provide a spring l8 which has a U-shaped portion I! and a pair ofdivergent arms 18 and 19, which arms underlie inclined surfaces 21 and22 respectively formed by the cut away portion of the base 5.

A fusible block 23 is positioned in the base and serves to hold thespring 16 in the position of Fig. 3, and while in this position thespring is under tension, so that the arms I8 and I9 press against theinclined surfaces 2i and 22 respectively.

The result of this construction is that when a fire does occur thetemperature of the room where my device is located will rise, and assoon as the same is high enough to melt the fusible block 23 the samewill collapse, as shown in Fig. 4.

This collapse is assisted by the downward pressure of the spring, as theends of the divergent arms [8 and I9 tend to cam along the inclinedsurfaces 21 and 22 respectively. It is unnecessary, therefore, for thefusible block to reach a point of actual melting but only to the pointof softening.

As the spring l6 moves downwardly, the arms [8 and [9 will engage thecontacts 8 and 9 respectively, and due to the tendency of spreading,these ends of the spring will dig into the contacts '8 and 9 and thusassure a very good electrical contact between the spring 16 and thecontacts 8 and 9; thus the circuit will be completed and the alarm willbe caused to function.

It will thus be seen that I have produced a device which will accomplishall of the objects above set forth.

It is to be understood that the form of my invention herewith shown anddescribed is to be taken as a preferred example of the same and thatvarious changes relative to the material, size, shape and arrangement ofparts may be resorted to without departing from the spirit of theinvention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. A switch for fire alarms, comprising a pair of spaced, verticallyarranged contacts, cam surfaces formed adjacent said contacts, aU-shaped spring having diverging arms engaging said cam surfaces, and afusible block supporting said spring, whereby said arms engage said camsurfaces under tension and maintain said arms out of engagement withsaid contacts.

DAN'IE PADILLA.

